1. Field of the Invention
The field of the present invention is reaction force type disk brakes primarily used in a vehicle, and more particularly, improvements in reaction force type disk brakes of a type including a brake disk; a first and a second friction pad which are opposed to opposite sides of the brake disk; a brake caliper having a first and a second clamping arm for clamping the friction pads therebetween, and a pair of bridge portions inter-connecting opposite ends of the respective clamping arms which are spaced from each other in a circumferential direction of the brake disk, the caliper having a window defined by the clamping arms and the bridge portions; an urging member mounted in the first clamping arm for urging the first friction pad against the brake disk; a stationary bracket disposed within the window in the vicinity of the bridge portions and having a pair of support portions on which the friction pads are slidably suspended; and a pair of slide pins provided on the support portions to extended parallel to an axis of rotation of the brake disk and slidably fitted in pin holes made at portions of the first clamping arm connected with the bridge portions.
2. Description of the Prior Art
The present applicant has previously proposed such a reaction force type disk brake, for example, in Japanese Utility Model Application Laid-open No. 80833/89.
In this reaction force type disk brake, each pin hole is formed so as to pass through the first clamping arm.
With such a construction, however, the connection of the first clamping arm with the bridge portion is reduced in rigidity. This causes a problem that the first clamping arm tends to be opened away from the brake disk, that is, the lower part of the first arm, and in many cases along with the lower part of the second arm, tends to be separated from the disk. As a result, the friction pads may unevenly wear through braking operations.
In order to solve the above problem, the first clamping arm may be increased in rigidity by increasing the wall thickness thereof. However, this brings about an increase in weight of the brake caliper, resulting in a failure to meet the demand for a reduction in weight of the reaction force type disk brake.